Improvement



A. S. GEAR.

Machines for Tu-rning Stone.

No. 136,432 I PatentedMarch4,l873.

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ALONZO S. GEAR, OF BOSTON, MASSACHUSETTS.

lhlPROVEM ENT lN MACHINES FOR TURNlNGSTQNE.

Specification forming part of Letters Patent N0. 136,432, dated March 4, 1873.

To all whom it may concern:

Be it known that I, ALONZO S. GEAR, of Boston, in the county of Suffolk and State of Massachusetts, have invented certain Improvements in Stone-Turning Machines, of which the following is a specification:

My invention relates to a rotary cutter-head studded with diamonds for turning stone; and it consists in the combination of such rotary cutter-head with the common well-known enginelathe, said cutter-head being connected to such engine-lathe in the place of the turning-tool 110w used, by means of suitable journal-boxes attached to a plate or bed-piece which is confined to the tool-stock in such manner as to admit of being moved laterally, and to permit a slight elevation or depression of the cutterhead, which is made to revolve at a very high rate of speed by means of a one-fourth twistbelt which passes around a flanged pulley upon a longitudinal arbor or shaft carrying such rotary cutter-head, whose cutting-face stands nearly in a vertical position, and connects with a drum overhead running at right angles with such cutter-head shaft, and being in line with the stone to be turned so as to allow said belt to traverse said drum as the cutter-head is carried along the lathe by a screwshaft connected to the cutter-stock in the usual manner for such purpose.

A pillar or column of stone to be turned is placed in the lathe in the same manner that a piece of iron would be if it was to be turned, and motion imparted to it by the lathe in the usual manner; then the swift-revolving rotary cutter-head, studded with diamonds, is brought in contact with the slow-revolving stone; the diamonds upon the periphery of such cutter-head cut away the highest projecting portions of the same by partially cutting in under the same when the rear bevel or rotary wedge upon the cutter-head comes in contact beneath such projections and chips or breaks them off; then the diamonds upon the face of the cutter-head further reducethe stone until it is turned to the size and shape desired; thus I am enabled to turn a pillar or column of stone or other article desired with the same facility that iron is turned at the present time in the common engine-lathe.

Figure 1 is a perspective view of the rotary cutter head studded with diamonds as detached from the engine-lathe. Fig. 2 is a vertical central section of the same, as indicated by dotted lines a: y, Fig. 1. Fig. 3 is a perspective view of the engine-lathe with rotary cutter-head as attached for use.

A A represents the common en gine-lathe ot' the usual construction, except the cutter-stock B, which is provided with means of attaching the base-plate D to its top, the bottom being attached to the semicircular base 0, or in any other preferred way, so as to admit of the elevation and depression of the cutter-head G. D is the base-plate containing the journalboxes E E in which the arbor F of the cutterhead G revolves; the periphery and outer portion of the face of the cutter-head G are studded with diamonds S S S, as shown in Fig 1.

This rotary cutter-head may be constructed of steel entire, or the rear portion may be of.

chilled cast-iron, and of any form desired, and from an inch to an inch and a half in diame ter, more or less, as desired, being constructed suitable to run at a very high rate of speed.

I have omitted to describe the engine-lathe with which my invention is combined 5 it being old and well-known I do not claim its invention, it being a distinct and separate machine of itself used for other purposes; but

\Vhat I claim as my invention, and desire to secure by Letters Patent, is-

In combination with an engine-lathe, a rotary cutter-head, studded with diamonds, for turning stone, substantially in the manner described, as and for the purposes set forth.

' ALONZO S. GEAR.

Witnesses:

SYLVENUS WALKER, L. W. BRADLEY. 

